Oil circuit breaker interrupter structure with removable external insulation tube



Nov. 8, 1966 Filed Sept. 13, 1963 E. B. RIETZ ETAL OIL CIRCUIT BREAKER I NTERRUPTER STRUCTURE WITH REMOVABLE EXTER NAL INSULATION TUBE 2 Sheets-Sheet Er-E. E.

ZZ Z4 INVENTORS IA/Q 5, ,e/E rz Nov. 8, 1966 E. B. RlETz ETAL OIL CIRCUIT BREA KER INTERRUPTER STRUCTURE W EXTERNAL INSULATION TUBE REMOVABLE 2 Sheets-Sheet Filed Sept. l5, 1963 United States Patent 3,284 603 p OIL CIRCUIT BREAKERINTERRUPTER STRUC- TURE WITH REMOVABLE EXTERNAL INSULA- TION TUBE Earl E. Rietz, La Canada, and Roy W. Lindberg, Sierra Madre, Calif., assignors to I.T.E. Circuit Breaker Cornpany, Philadelphia, Pa., a corporation of Pennsylvama Filed Sept. 13, 1963, Ser. No. 308,726 3 Claims. (Cl. 200-150) This invention relates to a novel interrupter structure for oil circuit breakers, and more specifically relates to a novel interrupter structure having improved performance wherein the outer insulation tube is removable independently of the internal interrupter construction to provide access for inspection, maintenance or replacement of all parts therein.

Interrupter structures of the multibreak type are well known to the art. Generally, the breaks within the in- Iterrupter have been positioned vertically one above the other. Moreover, complete disassembly of the interrupter has been required for inspection or maintenance, with the outer insulation tube remaining on the adapter which secures the interrupter structure to Ithe support bushing. The prior art has further provided structures wherein the baffle assemblies within the interrupter -could be removed without disassembly of the interrupter, although total maintenance has required total :disassembly of the interrupter with the outer tube remaining on the adapter.

In accordance with the present invention, a novel interrupter structure is provided using a plurality of series connected breaks, wherein the outer tube of the interrupter is removable from the adapter while the remaining interrupter structure remains secured to the adapter, whereby complete maintenance, repair and replacement may proceed without disturbing the alignment of the various parts.

Accordingly, a primary object of this invention is to provide a simple structure for oil circuit breaker interrupters which permit rapid assembly and disassembly of the interrupater structure without disturbing its alignment.

Another object of this invention is to provide a novel multibreak interrupter structure which is inexpensive in manufacture.

A further object of this invention is to provide a novel multibreak interrupter structure wherein inspection and maintenance is easily accomplished.

A still further object of this invention is to provide a novel interrupter structure which can be contained within a small volume to thereby be capable of being contained within a tank having a minimum size.

Another object of this invention is to provide a spring biased support for .the tie rods which support the baie assemblies.

A further object of this invention is to provide a novel interrupter structure which has improved performance over a Wide range of current interruption duty.

These and other objects of this invention will become apparent from the following description when taken in connection with the drawings, in which:

FIGURE 1 shows a side view of an interrupter structure made in accordance with the present invention and is partially in cross-section.

FIGURE 2 shows a side view of .the novel interrupter structure of the invention which is partially in cross-section across the lines 2 2 of FIGURE l.

FIGURE 3 shows a cross-sectional view of FIGURE 1 taken through lines 3 3 of FIGURE l.

FIGURE 4 shows a cross-sectional view of FIGURE 1 taken through the lines 4 4 of FIGURE 1.

FIGURE 5 shows a cross-sectional view of FIGURE 1 taken through the lines 5 5 of FIGURE 1.

FIGURE 6 shows the movable .contact ladder arrangement of the movable contact structure of FIGURES l and 2.

Referring iirst to FIGURES 1 and 2, the main support for the interrupter is comprised of a head casting 10 which has a portion 11 securable both mechanically and electrically to the end 12 of a bushing stud which will carry the interrupter structure within an `oil filled tank. If desired, this upper head casting portion can be appropriately covered with a corona shield 13. The casting 10 further defines a cylinder 14 which receives a piston 15. Piston 15 is biased downwardly by compression springs 17 in order to generate a relatively high pressure within the interrupter structure during interruption conditions, particularly lauded low fault current conditions.

A stationary contact plate 20 is then carried at the bottom of casting 10 and carries a circular cluster of stationary contacts 21 thereon in the usual manner, which contacts will receive an elongated movable contact in a manner to be described hereinafter.

The pla-te 20 then carries three insulating rods 22, 23 and 24 (FIGURES 4 and 5) where rods 22 and 24 are shown in FIGURE 2. It will be observed that rods 22, 23 and 24 passV through bale assembly 25, which will be described more fully hereinafter, and support the baille assembly 25 in any desired manner as by forming the rods of two sections which engage the assembly 25 on either of its sides in an intermediate necked-down portion of the rod.

The lower ends of rods 22, 23 and 24 terminate on a second stationary contact support plate 26. The stationary contact plate 26 carries the upwardly extending stationary Contact cluster 27 shown as including six stationary contacts in FIGURE 4, and a lower contact cluster 28, best shown in FIGURE 2.

The plate 26 then carries the upper ends of insulation rods 30, 31 and 32. As best seen in FIGURES 2 and 4, the rods 30, 31 and 32 may have necked-down portions such as necked-down portion 33 ofrod 32 of FIGURE 2, which pass through and rigidly secure baille assembly 34, which may be identical in construction to assembly 25, but vents 180 from the venting direction of baffle assembly 25. The ends of rods 30, 31 and 32 are then terminated by an extended head bolt 35 which carries a spring 36 thereon.

Preferably, tie rods 22, 23, 24, 30, 31 and 32 engage plate 26 through a spring lmeans (not shown) captured between the ends of the rods and the plate. This novel arrangement oifers relief of excessive forces applied to the rods during interrupting conditions, and keeps all loading in compression.

From the foregoing, all of the components described are carried from the head casting 10, and are independent of the interrupter housing, which will be described hereinafter.

The movable contact structure for the interrupter is best shown in FIGURE 6 as being comprised of a ladder arrangement which includes movable conductive contact` members 40, 41 and 42. The ladder arrangement is formed of conductive rung 43 which carries elongated contacts 40 and 41, a conductive rung 44 (FIGURE 4) which carries contact 42 and an upper U-shaped conductive rung 45. Rungs 44 and 45 are held in rigid spaced relationship with respect to one another by insulated rods 46 and 47, while rungs 43 and 44 are spaced by similar insulation rods 48 and 49.

Referring now particularly to FIGURES l and 2 which show the interrupter in its closed condition, it will be seen 42 engages Istationary contact 21. The lower end of contact 42 and conductive bridge or rung 44 `is in engagement with stationary contacts 27. The lower end of stationary contact plate 26 and, more specifically, the stationary contacts 28, `are engaged by the upper end of contact 41. The bottom of contact 41 then extends through rung or bridge 43 to contact 40. The lower end of contact 40 then engages a cooperating contact formed by a conductive cross-bar partially shown as cr-oss-bar 50 which is moved by an appropriate. operating mechanism within the oil tank.

Thus, an electrical circuit is formed from head casting 10, stationary contact 21, movable contact 42, station-ary contact 27, stationary contact 28, movable contact 41, movable contact 40, and cross-bar 50.

Tlhe upper ends of the U-shaped bridge element 45, as best shown in FIGURE 1, are formed by hollow tubular portions 51 andy 52. As best shown for hollow tubular portion 51 in FIGURE 1, a plurality of compression springs 53 and 54 are contained therein to normally bias the movable contact ladder downwardly. In order to retain the movable contact structure in the engaged position shown, an appropriate Iforce is applied to the cross-bar 50 to hold the contacts in the position shown against the force of these springs. It will be further noted that the cross-bar 50 also retains piston 15 in its uppermost position sho/wn in FIGURES l and 2 against the force of the piston biasing spring 17 by virtue of engagement between the central portion of ladder member 45 and piston 15.

Moreover, the movable contact structure will normally be held in position with respect to the stationary contact entry in to the interrupter when tJhe interrupter is closed.

Further openings such as openings 90 and 91 are provided in the bushing for receiving the end portions of rods 48 and 49 of the movable contact .assembly (opening 90 receives extending portion 92 of rod 48, while opening 91 receives portion 93 of bridge 43). These openings operate to provide a dashpot-type effect when the movable contact is moved to its open position.

If desired, further bolt means can be provided which pass through housing 70 such as bolt means 90 which is secured to conductive plate 26 to align plate 26.

It will now be understood that the complete interior of the interrupter structure can be exposed for maintenance,

stnucture in the absence of other support means lwhere, for

example, the ladder sections 44 and 45 would be stopped from further downward movement by their respective stationary contact means. For example, cross-arm 44 would hit the top of plate 60.

Returning now to the baffle assemblies 25 and 34, the assemblies, as best shown in FIGURE 2 for assembly 34, are formed of a plurality of spacer plates 60, 61, 62 and 63 and splitter plates 64, 65 and 66. The splitter plates and spacer plates are appropriately located 'with respect to venting ports 67, 68 and 69 of housing 70 so that venting will occur through these ports during interruption conditions. It will be further noted that valve members 71, 72 and 73, which are constructed in accordance with the novel valve structure of copending application Serial No. 190,381, filed April 26, 1962 in the name of James R. McCloud, entitled Inter-rupter Structure and assigned to the assignee of the present invention, are contained between adjacent spacer plates to insure adequate buildup of pressure under low fault current conditions.

The bafiie assembly 25, as pointed out above, is constructed in a manner similar to assembly 34 with the exception of being rotated by 180. Thus, venting from baffie assembly 25 will take place through vents 74, 75 and 76. This novel relationship between the venting ports will cause a cancellation of reaction forces generated by blasting from assemblies 25 and 34, so as to reduce cantilever force-s on the bushing having stud 12 which supports the entire interrupter assembly.

In order to novv enclose the interrupter structure described, the hollow insulator tube 70 is provided, as-shown in FIGURES 1 and 2. More specifically, tube 70l is provided With a-n extended upper portion l80 which receives a clamping ring 81 which can be threadably secured to conductive plate 20 )by appropriate bolt means such as bolt 82 of FIGURE 2. 'Ilhe bottom of interrupter housing 70 has an inwardly necked section 83 which receives an insulation throat bushing 84 which has an opening therein yfor passing contact 40, and encloses the bottom of the interrupter structure.

The disk-shaped throat bushing 84 also has openings therein, such as openin-g 85 of FIGURE 2,'vvhich receives the head 35 at the bottom of rod 32 and the similar heads of rods and 31, whereupon the biasing spring such as spring 36 seats on the upper surface of throat brushing 184. This -then provides a positive biasing force for biasing the assembly together. A second portion of bushing 84 may then have a valve structure 86 which permits oil inspection and replacement by merely removing the bolts such as bolt 82 from retaining ring 81 and plate 20, whereupon the complete housing can be moved downwardly and off of the interrupter structure. The interrupter structure, however, remains in position, and any critical alignment between the components therein is not disturbed. Maintenance, inspection and replacement may then be undertaken without requiring removal of the interrupter structure from tfhe head casting 10.

If desired, the :interrupter ystructure may be further modified to have a parallel resistor stack secured between the conductive member 20 at its upper end, and a conductive terminal 10d at the bottom of the interrupter housing. The terminal 101 may then be electrically connected to the auxiliary contacts 102 which engage contact 40, as shown in FIGURE l. Thus, the resistor 100 (or a plurality of resistors around the periphery of tube 70) wil-l Ibe electrically connected between contact 40 and plate 20. Such resistor .means may be desirable in order to divide voltage between t'wo series connected interrupters within a common tank, as is usually provided.

When resistors are provided in lthis manner, lit will be noted that the interrupter housing 70 can still be removed from the interrupter structure.

When the interrupter is moved to its disengaged position by the downward motion of cross-bar 50, -it will be observed that piston 15 will be driven downwardly by its compression spring 17. This will create a higlh pressure rwithin the interrupter structure, and will provide a flow of fluid downwardly -and out through the venting ports.

The cylinder l16 has openings such as opening 110 in the lower part thereof and a second opening 111 in the upper portion thereof. The opening 111 is slightly larger in diameter than the thickness of the piston engaging ring surface 112. Thus, when the piston is in its upper position, as best illustrated in FIGURE 2, the opening 111 is made quite small which is sufficient only to permit oil circulation through the interrupter by oil coming through valve 86 -to cool the interior interrupter components. During circuit interrupt-ion, however, the valve opening 111 is completely open, since the piston moves upwardly to thereby provide for blast relief so that excessively large pressures cannot be built up within the interrupter. The opening, however, is not large enough to prevent a sufficient build-up of pressure within the interrupter to provide effective interruption of the low current faults.

Although this invention has been described with respect to preferred embodiments thereof, it is to be understood that many variations and modifications will now be obvious to those skilled in the art, and it is preferred, therefore, that the scope of this invention be limited not by the specific disclosure herein but only by the appended claims.

The embodiments of the invention in which an exclusive privilege or property is claimed are defined as follows:

1. In combination; an interrupter structure, an insulation housing for said interrupter structure and a mounting support for said interrupter structure and said hosing; said interrupter structure being secured to said mounting support -by first mounting means; said insulation housing enclosing said interrupter structure and being connected to said support by second mounting means;

said insulation housing being removable from said common support to expose said interrupter structure by removal of said second mounting means; said common mounting support including oil pressure generating means communicating with the interior of said insulation housing; sai-d oil pressure generating means comprising a pis ton movable within a cylinder; said cylinder having an opening therein; said piston enclosing a portion of said opening when said interrupter is closed; the open portion of said partially enclosed opening deilning .a ilow path for `circulation of oil; said opening being completely exposed when said piston is moved within said cylinder.

2. An interrupter structure for an oil circuit breaker; interrupter stnucture including a movable contact assembly, a stationary contact assembly and a baille asembly surrounding said movable contact asembly and receiving the arc generated when said movable contact assembly moves to a disengaged position with respect to said stationary contact asembly; said movable contact assembly, stationary contact assembly and baille assembly being supported from a common support means; an insulation housing for enclosing said movable contact assembly, stationary contact assembly, and baille assembly; said insulation housing being secured to and removable from said common support means independently of said movable contact assembly, stationary ycontact assembly and baille assembly; said common support means `defining a cylinder; said cylinder having a biased piston movable therein; said piston being engaged by said movable contact assembly; said piston being moved toward a pressure generating position when said movable contact moves t0 a disengaged position; said cylinder and piston communieating with the interior of said insulation housing.

3. The device substantially as set forth in claim 2 which includes a plurality of tie rods extending from said common support means and securing means for securing said plurality of tie rods to said stationary contact assembly; -said securing means including resilient means for permitting small relative movement between said tie rods and said stationary contact assembly for stress relief during interruption condition-s.

References Cited by the Examiner UNITED STATES PATENTS 2,055,345 9/1936 Flurscheim ZOO-150 2,134,569 10/1938 MacDonald et al. 200-150 2,619,568 11/1952 Leeds 200-159 2,667,556 1/1954 Van Sickle et al. 200--150 3,180,959 4/1965 MacNeill et al ZOO-150 ROBERT K. SCHAEFER, Primary Examiner. ROBERT S. MACON, Examiner. 

1. IN COMBINATION; AN INTERRUPTER STRUCTURE, AN INSULATION HOUSING FOR SAID INTERRUPTER STRUCTURE AND A MOUNTING SUPPORT FOR SAID INTERRUPTER STRUCTURE AND SAID HOSING; SAID INTERRUPTER STRUCTURE BEING SECURED TO SAID MOUNTING SUPPORT BY FIRST MOUNTING MEANS; SAID INSULATION HOUSING ENCLOSING SAID INTERRUPTER STRUCTURE AND BEING CONNECTED TO SAID SUPPORT BY SECOND MOUNTING MEANS; SAID INSULATION HOUSING BEING REMOVABLE FROM SAID COMMON SUPPORT TO EXPOSE SAID INTERRUPTER STRUCTURE BY REMOVAL OF SAID SECOND MOUNTING MEANS; SAID COMMON MOUNTING SUPPORT INCLUDING OIL PRESSURE GENERATING MEANS 